Background: The effects of prenatal particulate matter with an aerodynamic diameter ranging from 0.1 mm to 2.5 mm (PM 2.5 ) and vitamin D on atopic dermatitis (AD) phenotypes have not been evaluated. DNA methylation and cord blood (CB) vitamin D could represent a plausible link between prenatal PM 2.5 exposure and AD in an offspring. Objective: To determine the critical windows of prenatal PM 2.5 exposure on the AD phenotypes, if vitamin D modulated these effects, and if placental DNA methylation mediated these effects on AD in offspring. Methods: Motherechild pairs were enrolled from the birth cohort of the Cohort for Childhood Origin of Asthma and allergic diseases (COCOA) study. PM 2.5 was estimated by land-use regression models, and CB vitamin D was measured by chemiluminescence immunoassay.

These data suggest that alterations in the composition and function of the upper airway microbiome could be related with the natural course of asthma in children.

Background Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease. Great efforts have been recently made to treat AD using mesenchymal stem cells (MSCs), which have immunomodulatory functions. However, the immunomodulatory effects of MSCs need to be enhanced for clinical application in the treatment of AD. Objectives To evaluate and characterise the therapeutic effects of human Wharton’s jelly-derived MSCs (WJ-MSCs) primed with the Toll-like receptor 3 agonist poly I:C or interferon-γ (IFN-γ) in a murine model of AD. Methods Mice were treated with Aspergillus fumigatus extract to induce AD and then subcutaneously injected with non-primed, poly I:C-primed or IFN-γ-primed WJ-MSCs. Clinical symptom scores, transepidermal water loss (TEWL), histological characteristics and cytokine levels were determined. Transcriptome profiling and pathway analyses of primed WJ-MSCs were conducted. Results The clinical symptom score and TEWL in skin lesions were reduced in mice administered non-primed and primed WJ-MSCs. Epidermal thickness and inflammatory cell infiltration in skin lesions were reduced more in mice administered primed WJ-MSCs than in mice administered non-primed WJ-MSCs. Secretion of interleukin-17 was significantly reduced in skin draining lymph nodes of mice administered primed WJ-MSCs. Genomics and bioinformatics analyses demonstrated the enrichment of certain pathways specifically in WJ-MSCs primed with poly I:C or IFN-γ. Conclusions Priming with poly I:C- or IFN-γ improved the therapeutic effects of WJ-MSCs in a murine model of AD. This study suggests that priming with poly I:C or IFN-γ enhances the immunomodulatory functions of WJ-MSCs and can be used as a novel therapeutic approach for AD. Electronic supplementary material The online version of this article (10.1186/s13287-019-1164-6) contains supplementary material, which is available to authorized users.